The White House has released President Obama's long-form birth certificate, saying the document is "proof positive" the president was born in Hawaii.

The release marked an unexpected turn in the long-simmering, though widely discredited, controversy over Obama's origin. Obama's advisers have for the better part of three years dismissed questions about the president's birth, directing skeptics to the short-term document released during the 2008 campaign. But as the issue gained more attention at the state level and particularly in the 2012 presidential race, Obama said Wednesday that it was starting to distract attention from pressing challenges like the budget.

The president, who discussed the release at the White House without taking questions, said he had been "puzzled" by the enduring shelf life of the issue and acknowledged the announcement may not put the so-called birther controversy to rest. But he told the public and the media that it's time to "get serious."